MxU networking architecture is known in the art and is used to provide communication services to a site (e.g., an apartment building) which includes a plurality of substantially independent sections (e.g., a plurality of apartments), each associated with a different subscriber. In general, the MxU networking architecture defines a separate local area network (LAN) for each of the sections.
MxU networks which are based Home Phoneline Networking Alliance (HPNA), use the telephone lines of the telephone wire network, already installed in the MxU. Each of the LANs includes the telephone wires which are associated with a selected section (e.g., apartment) and a plurality of HPNA nodes coupled with the telephone outlets. Telephone network voice communication and data communication services can be used simultaneously, using a technique known as frequency division multiplexing (FDM). Accordingly, data signals are transmitted using a different (higher) frequency than voice data signals, whereby these signals, can be separated using a frequency splitter.
Reference is now made to FIG. 1, which is a schematic illustration of an apartment building network, generally referenced 10, which is known in the art. It is noted that FIG. 1 is not drawn to scale.
Apartment building network 10 includes intra-apartment networks APT1 (referenced 121), APT2 (referenced 122) and APTN (referenced 12N), and gateways G1 (referenced 221), G2 (referenced 222) and GN (referenced 22N). Gateways 221, 222 and 22N are mounted on a platform 16. A broadband source 20 couples each of gateways 221, 222 and 22N with a wide area network (WAN) such as the Internet, via a broadband link such as xDSL, cable, fiber-optic, satellite, Local Multipoint Distribution System (LMDS), and the like.
Each of intra-apartment networks 121, 122 and 12N includes several network nodes (not shown). Each one of gateways 221, 222 and 22N is coupled with a respective one of intra-apartment networks 121, 122 and 12N, via respective telephone wires 141, 142 and 14N. Each one of the gateways 221, 222 and 22N, and a respective one of intra-apartment networks 121, 122 and 12N, together form a respective one of local-area networks (LAN) 141, 142 and 14N. Each of LANs 141, 142 and 14N is further coupled with telephone service lines 241, 242 and 24N, respectively.
Reference is now made to FIGS. 2A and 2B. FIGS. 2A and 2B schematically illustrate an apartment building network, generally referenced 40, which is known in the art. FIGS. 2A and 2B show a first and second example of NEXT in an MxU network, respectively. It is noted that FIGS. 2A and 2B are not drawn to scale.
With reference to FIG. 2A, apartment building network 40 includes intra-apartment networks APT1 (referenced 421), APT2 (referenced 422) and APTN (referenced 42N), gateways G1 (referenced 521), G2 (referenced 522) and GN (referenced 52N), and phone wires 541, 542 and 54N. A wire binder 48 runs from a basement 44 of the apartment building, to the vicinity of intra-apartment networks 421, 422 and 42N. A platform 46 is located in basement 44. Gateways 521, 522 and 52N are mounted on platform 46. A broadband source 50 couples each of gateways 521, 522 and 52N with a WAN such as the Internet, via a broadband link such as xDSL, cable, fiber-optic, satellite, Local Multipoint Distribution System (LMDS), and the like.
Each of intra-apartment networks 421, 422 and 42N includes several network nodes (not shown), as shall be described in further detail with reference to FIG. 2C. Each one of gateways 521, 522 and 52N is coupled with a respective one of intra-apartment networks 421, 422 and 42N, via respective phone wires 541, 542 and 54N. Each combination of one of the gateways 521, 522 and 52N, the respective one of phone wires 541, 542 and 54N, and the respective one of intra-apartment networks 421, 422 and 42N, together form a respective one of local-area networks (LANs) 451, 452 and 45N. Phone wires 541, 542 and 54N are bound together in binder 48.
Gateway 521 transmits a data signal 56 to intra-apartment network 421. Simultaneously, intra-apartment network 422 transmits another data signal 58 to gateway 522. In a region 62, located in the vicinity of platform 46, an electrical disturbance 60, associated with data signal 56 (from phone wire 541), is induced in phone wire 542, causing an interference in data signal 58.
It is noted that conventionally, the distance between intra-apartment network 422 and region 62 is significantly greater than the distance between gateway 521 and region 62. Therefore, data signal 58 undergoes a significantly greater attenuation than data signal 56, before these data signals reach region 62, and hence, electrical disturbance 60 may cause a significant interference in data signal 58. This effect is known as near-end crosstalk (NEXT). It is noted that the transfer of disturbance 60 from phone wire 541 to phone wire 542 is a cumulative effect, which takes place all along phone wires 541 and 542, with a primary contribution occurring in region 62.
With reference to FIG. 2B, gateway 521 transmits a data signal 70 to intra-apartment network 421. Simultaneously, intra-apartment network 421 transmits another data signal 72 to gateway 522. In a region 76, located in the vicinity of intra-apartment networks 421 and 422, an electrical disturbance 74, associated with data signal 72 (from phone wire 542), is induced in phone wire 541, causing an interference in data signal 70.
It is noted that conventionally, the distance between gateway 521 and region 76 is significantly greater than the distance between intra-apartment network 421 and region 76. Therefore, data signal 70 undergoes a significantly greater attenuation than data signal 72, before these data signals reach region 76, and hence, electrical disturbance 74 may cause a significant interference in data signal 70.
Reference is further made to FIG. 2C, which is an illustration in detail of intra-apartment networks 421 and 421 of apartment building network 40 (FIGS. 2A and 2B) and a portion of the binder 48. FIG. 2C shows a third example of NEXT in an MxU network. It is noted that FIG. 2C is not drawn to scale.
Intra-apartment network 421 includes network nodes 801, 802 and 803. Nodes 801, 802 and 803 are coupled there between via phone wire 541. Intra-apartment network 422 includes nodes 821 and 822. Nodes 821 and 822 are coupled there between via phone wire 542.
Gateway 522 (FIG. 2A) transmits a data signal 86, through phone wire 542, toward intra-apartment network 422. Simultaneously, node 801 transmits another data signal 88 toward node 802.
It is noted that conventionally, data signal 88 includes a header with source and target attributes. All of the nodes of LAN 451 (FIG. 2A) receive data signal 88, but only the target node, which is specified in the source-target attributes (i.e., node 802) addresses and decodes the data signal. It is noted that in the description that follows and the accompanying drawings, except for the present example, data signals are only shown on their path to their intended receiving node.
Data signal 88 passes through phone wire 541 toward binder 48. In a region 84 in the vicinity of intra-apartment networks 421 and 422, an electrical disturbance 92, associated with data signal 88 (from phone wire 541), is induced in phone wire 542, causing an interference in data signal 86. Similarly as in the example set forth in FIGS. 2A and 2B, electrical disturbance 92 may cause a significant interference in data signal 86.